In the book trilogy The Summer I Turned Pretty by Jenny Han, Belly ultimately ends up with Conrad Fisher, the older brother of Jeremiah. Throughout the series, Belly has complicated relationships with both brothers. Initially, she dates Jeremiah and they become engaged despite some turmoil, including Jeremiah cheating on her during college. Belly breaks off the engagement after discovering his betrayal. Meanwhile, her longstanding feelings for Conrad resurface. Conrad confesses his love for her and, after some emotional struggles and time apart, they rekindle their relationship. The series concludes with Belly and Conrad getting back together, and Conrad proposing marriage to her. They marry and start a new life together, ending the story as a couple

. In summary:

• Belly dates Jeremiah for a time and gets engaged to him.
• Jeremiah cheats on Belly, leading to their breakup.
• Belly reconnects with Conrad, who has always loved her.
• Belly and Conrad reunite, get engaged, and marry by the end of the books